The present invention relates to an internal-pressure detect ion apparatus for a pneumatic fender.
Conventionally, in order to prevent a ship from contacting to or being damaged due to collision within underwater structure such as a bridge pier and a quay, contact of the ship to the underwater structure is prevented by fixing pneumatic fenders to the underwater structure or floating pneumatic fenders on the water.
Such a pneumatic fender is made as cushioning material fill ed with air inside the pneumatic fender, and hence, if its air pressure decreases due to leakage of internal air, its function is impaired. For this reason, the internal air pressure is kept at a designated value by measuring the air pressure inside the fender through periodical patrol and supplementing the fender, whose internal air pressure is decreased, with air.
Nevertheless, since it requires much labor to check the air pressure inside the fender by manual patrol, systems monitoring the air pressure of the fender by using cables (Japanese Utility Model Application No. 61-112243) or a radio wave (Japanese Patent Application Laid-Open No. 60-46438) are also used.
Nevertheless, in a system monitoring air pressure of each fender using cables as disclosed in the Japanese Utility Model Application No. 61-112243, it was necessary to connect each fender to a monitoring station with a hose, and hence it needed not only much labor to install the system, but also much time to maintain the system itself.
In addition, in a system monitoring air pressure inside a fender using a radio wave as disclosed in Japanese Patent Application No. 60-46438, a battery has been used in a transmitter (radio wave transmitter) provided in the fender. Therefore, in order to prevent the transmitter from stopping operation, it was necessary to periodically replace this battery. Hence, although installation of the system has been comparatively easy, this system has been a problem that it requires much labor to maintain the system.
An object of the present invention is, in consideration of above problems, to provide an internal-pressure detection apparatus for a pneumatic fender that can reduce the labor of installation and maintenance.
In order to attain the object described above, the present invention provides not only an internal-pressure detection unit in a pneumatic fender that is fixed to an underwater structure or floated and is used as cushioning material for a ship or the like, but also a monitor unit in an internal-pressure monitoring station Furthermore, the present invention transfers an air pressure value inside the pneumatic fender, which is detected by the internal-pressure detection unit, to the monitor unit by an electromagnetic wave, and thereby makes it possible to monitor internal air pressure of all the pneumatic fenders, which are objects to be monitored, in the internal-pressure monitoring station.
The internal-pressure detection unit described above converts the energy of an electromagnetic wave having a first frequency, which is received by means of reception, into electric energy, and thereby operates by this converted electric energy. Furthermore, the internal-pressure detection unit detects the air pressure inside a pneumatic fender by a pneumatic sensor, and transmits this detection result by an electromagnetic wave having a second frequency.
On the other hand, the monitor unit described above not only supplies operation energy to the internal-pressure detection unit by transmitting the electromagnetic wave, having the first frequency by means of transmission, but also informs of a detection result of the air pressure by receiving the electromagnetic wave having the second frequency that is transmitted from the internal-pressure detection unit.
For example, the internal-pressure detection unit described above comprises a pneumatic sensor that detects air pressure inside a pneumatic fender and outputs an electric signal corresponding to the air pressure value, means of reception for receiving an electromagnetic wave having a first frequency, means of energy conversion for converting the energy of the electromagnetic wave, received by the means of reception, into electric energy, and means of transmission for operating by this converted electric energy, inputting an electric signal outputted from the pneumatic sensor, and transmitting a detection result of the air pressure by an electromagnetic wave having a second frequency.
In addition, the monitor unit described above comprises means of transmission for transmitting the electromagnetic wave having the; first frequency, means of reception for receiving the electromagnetic wave having the second frequency and converting the electromagnetic wave into an electric signal, means of detection result extraction for extracting the detection result of the air pressure, which is included in the electric signal outputted from the means of reception, and means of information for informing of the detection result extracted
According to the internal-pressure detection apparatus for a pneumatic fender that has the configuration described above, in the internal-pressure detection unit, the electromagnetic wave having the first frequency that is transmitted from the monitor unit is received by the means of reception. Furthermore, the energy of this electromagnetic wave is converted into electric energy by the means of energy conversion, and is supplied to the pneumatic sensor and the means of transmission.
Thereby, the internal-pressure detection unit operates by the energy of the electromagnetic wave having the first frequency received and hence it is unnecessary to provide any power supply such as a storage cell. Hence, it is unnecessary to periodically replace the storage cell, and hence it is possible to omit the labor of maintenance.
Furthermore, the air pressure of the pneumatic fender is detected by the pneumatic sensor in the internal-pressure detection unit, and an electric signal corresponding to the air pressure value detected is outputted from the pneumatic sensor. This electric signal is inputted to the means of transmission, and the detection result of the air pressure is transmitted by the electromagnetic wave having the second frequency.
On the other hand, in the monitor unit, the electromagnetic wave having the first frequency is transmitted by the means of transmission at the time of detecting the air pressure, and the electromagnetic wave having the second frequency that is transmitted from the internal-pressure detection unit is received by the means of reception and is converted into an electric signal.
The detection result of the air pressure that is included in the electric signal outputted from the means of reception is extracted by the means of detection result extraction, and then this detection result extracted is informed by the means of information.
Therefore, it is unnecessary to install cables between the pneumatic fender and monitoring station, and hence it is possible to omit the labor of installing cables like the conventional example.
In addition, by not only providing, in the internal-pressure detection unit, means of identification-information memory for storing the identification-information inherent in each internal-pressure detection unit, and means of transmission for transmitting this identification-information and the detection result of the air pressure by the electromagnetic wave having the second frequency, but also providing, in the monitor unit, means of detection result extraction for extracting the detection result of the air pressure and identification-information from the electric signal outputted from the means of reception, and means of information for informing of the extracted identification-information and detection result in a one-to-one correspondence between them, it becomes possible to identify the detection result transmitted from the internal-pressure detection unit mounted to each pneumatic fender if there are a plurality of pneumatic fenders that are objects to be managed.
That is, the identification-information inherent in each internal-pressure detection unit is stored in the means of identification-information memory, and the detection result of the air pressure and the identification-information are transmitted by the means of transmission in the internal-pressure detection unit by the electromagnetic wave having the second frequency.
Furthermore, in the monitor unit, the detection result of the air pressure and the identification-information are extracted by the means of detection result extraction, and then the means of information informs a monitoring person of this extracted identification-information and detection result in a one-to-one correspondence between them.
Thereby, when each detection result of the plurality of internal-pressure detection units is monitored at one monitor unit, the internal-pressure detection result of each pneumatic fender can be identified on the basis of the identification-information.
In addition, by providing, in the internal-pressure detection unit, means of identification-information extraction for extracting identification-information included in a high-frequency signal received by the means of reception, means of identification-information matching decision for deciding matching this identification-information extracted to own identification-information stored in the means of identification-information memory, and the means of transmission drive control for driving the means of transmission when matching according to this decision result, and providing, in the monitor unit, the means of memory for storing the identification-information of internal-pressure detection units provided in the pneumatic fenders that are objects to be detected, and means of transmission for transmitting this stored identification-information, which is stored, by the electromagnetic wave having first frequency, it becomes possible to obtain the detection result of the air pressure by designating one from among the plurality of pneumatic fenders that are objects to be managed.
That is, at the time of detecting the air pressure, in the monitor unit, the identification-information, which is stored in the means of memory, of the internal-pressure detection unit provided in the pneumatic fender that is an object to be detected is transmitted by the means of transmission by the electromagnetic wave having the first frequency.
Furthermore, in the internal-pressure detection unit, the identification-information included in the high-frequency signal received by the means of reception is extracted by the means of identification-information extraction. Matching this identification-information extracted to the own identification-information stored in the means of identification-information memory is decided by means of the identification-information matching decision. Then, when matching according to this decision result, the means of transmission is driven by the means of transmission drive control, and the own identification-information and detection result of the air pressure are transmitted.
Thereby, if there are a plurality of pneumatic fenders that are objects to be managed or there are a plurality of internal-pressure detection units, it becomes possible to transmit the detection result by designating an arbitrary internal-pressure detection unit.
In addition, by not only providing, in the internal-pressure detection unit, means of instruction extraction for extracting an information-read instruction and an information-write instruction which are included in the high-frequency signal received by the means of reception, means of identification-information matching decision for deciding matching the identification-information extracted by the means of identification-information extraction to the identification-information stored in the means of identification-information memory, means of information memory, the means of information write for writing information, which is an object to be written and follows an information-write instruction, into the means of information memory when matching according to the decision result of means of the identification-information matching decision and receiving the information-write instruction, the means of information read for reading information, which is stored in the means of information memory, when matching according to the decision result of means of the identification-information matching decision and receiving the information-read instruction, and means of transmission for transmitting this information which is read by the electromagnetic wave having the second frequency, but also providing, in the monitor unit, the means of instruction input for inputting an information-write instruction and information, which is an object to be written, to the means of information memory in the internal-pressure detection unit, and an information-read instruction from the means of information memory, the means of information extraction for extracting the information that is stored in the internal-pressure detection unit and is included in the electric signal outputted from the means of reception, means of transmission for transmitting the instructions and information, which are inputted by the means of instruction input, by the electromagnetic wave having the first frequency, and mean""s of information for informing a monitoring person of the information extracted by the means of information extraction, it becomes possible to allow a pneumatic fender itself to store and hold information such as maintenance records by recording the information, being inherent in each pneumatic fender, in the means of information memory of the internal-pressure detection unit, and to access this information according to necessity.
That is, if the information-write instruction or information-read instruction is inputted by the means of instruction input in the monitor unit, these instructions are transmitted by the means of transmission by the electromagnetic wave having the first frequency.
The instructions transmitted from the monitor unit by the electromagnetic wave having the first frequency are received by the means of reception in the internal-pressure detection unit. These information-read instruction and information-write instruction, which are included in the high-frequency signal received, are extracted by the means of instruction extraction in the internal-pressure detection unit.
Furthermore, in the internal-pressure detection unit, matching the identification-information, which is extracted by the means of identification-information extraction, to the own identification-information stored in the means of identification-information memory is decided by means of the identification-information matching decision. When matching according to the decision result and receiving the information-write instruction, information that is an object to be written and follows this information-write instruction is written into the means of information memory by the means of information write.
In addition, when matching according to the decision result, of means of the identification-information matching decision and receiving the information-read instruction, information that is stored in the means of information memory is read by the means of information read at the internal-pressure detection unit. This information read is transmitted by the means of transmission by the electromagnetic wave having the second frequency.
Furthermore, the information transmitted from the internal-pressure detection unit is received by the monitor unit, and is informed by the means of information.
Thereby, it becomes possible to access information in the means of information memory of the internal-pressure detection unit as the need arises.